In reply to Quentin.

Quentin,

Yes, they show up in PROC CONTENTS (which is really the same as PROC DATASET and the CONTENTS statement, essentially).

And there is a SASHELP.VXATTR for your querying convenience. Example:

proc sql;
select name, xattr,xtype,xvalue from sashelp.vxattr
where libname="WORK" and memname="CARS";
quit;

Partial output:

Extended
Attribute Extended Attribute
Column Name Extended Attribute Name Type Value
--------------------------------------------------------------------------
STATUS char Added cardinality on
18OCT13
Make pct_unique num 0.0887850467
Make nlevels num 38
Model pct_unique num 0.9929906542
Model nlevels num 425
Type nlevels num 6
Type pct_unique num 0.0140186916
Origin nlevels num 3
Origin pct_unique num 0.0070093458
DriveTrain nlevels num 3
DriveTrain pct_unique num 0.0070093458
MSRP pct_unique num 0.9579439252
MSRP nlevels num 410
Invoice nlevels num 425
Invoice pct_unique num 0.9929906542